Security screw



FIG. 1 is a front, top, right side perspective view for a security screw, showing our new design;

FIG. 2 is a front, top perspective view thereof;

FIG. 3 is a rear, top perspective view thereof;

FIG. 4 is a front elevational view thereof; and,

FIG. 5 is a top plan view thereof. 

CLAIM The ornamental design for a security screw, as shown and described. 